Unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
A particle-in-binder (PIB) detector is used in an X-ray imager for converting X-ray into electrical signals. In a traditional PIB detector, X-ray sensitive particles are distributed in a charge transporting binder, which is sandwiched between two electrodes. Upon impingement of X-ray photons, the X-ray sensitive particles generate charge carriers (i.e., electrons and holes). The two electrodes are biased in order to create an external field, which draws the generated electrons and holes toward opposite sides of the PIB detector. After collecting the electrical charges accumulated on the electrodes, corresponding images associated with the X-ray exposure may be generated.
One major drawback of the traditional PIB detector is its unstable charge transfer characteristics at the interface between the surfaces of the X-ray sensitive particles and the charge transporting binder. Due to variations in temperature, impurities or moisture during manufacturing processes, the X-ray sensitive particles may trap varying amount of charge carriers at the surfaces. Depending on the location of an X-ray sensitive particle, a charge carrier generated by the X-ray sensitive particle may travel a long distance or a short distance before reaching one side of the PIB detector. These varying charge transfer characteristics and carrier drift distances may limit the conversion efficiency of the X-ray imager.